Texas Instruments AN-1521 POEPHYTEREV-E Скачать руководство пользователя страница 14 | Manualshive

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Texas Instruments AN-1521 POEPHYTEREV-E Скачать руководство пользователя страница 14

PoE Performance Characteristics

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Horizontal Resolution: 5 ms/div.
Trace 1: The voltage of the RTN pin (referenced to the VEE pin). 0.5V/div.
Trace 2: The PoE input current. 0.5A/div

Figure 9. Retry Mode under 38V PoE Input and Output Over Current Condition

22.4 Step Response

Figure 10

shows the step load response at Vin equal to 48V. The load current changes in step between

1A and 7A.

Horizontal Resolution: 0.5 ms/div.
Trace 1: Load current step changes between 1A and 7A. 2A/div.
Trace 2: The 3.3V output voltage response (AC coupled). 0.5V/div.

Figure 10. Output Voltage Step Load Response

14

AN-1521 POEPHYTEREV-I / -E Evaluation Board

SNOA476C – October 2006 – Revised April 2013

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Copyright © 2006–2013, Texas Instruments Incorporated

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Содержание AN-1521 POEPHYTEREV-E

Страница 1: ...ion kit EK is designed for high power PD PoE terminology Powered Device applications in which the maximum power exceeds the IEEE 802 3af s 12 95W limit The evaluation board features TI s DP83848 10 10...

Страница 2: ...oltage ranges PoE input voltage range 39 to 57V AUX input voltage range 22 to 57V Measured maximum efficiency DC to DC converter efficiency 90 at 6A Overall efficiency including the input diode bridge...

Страница 3: ...1h The board may be set to PHY Address 03h by adding jumper J3 Table 1 Table of Jumpers 1 Jumper Name Function J1 MII Male Connector MII interface J2 MII Header Alternative connection for MII signals...

Страница 4: ...oper cable at such power levels may violate safety regulations and may cause damage 7 A Note about PoE Input Potentials PoE applications are typically 48V systems in which the notations GND and 48V no...

Страница 5: ...tic Part 1 The Ethernet Circuit Figure 2 Evaluation Board Schematic Part 2 RJ45 connectors and Ethernet Magentics 5 SNOA476C October 2006 Revised April 2013 AN 1521 POEPHYTEREV I E Evaluation Board Su...

Страница 6: ...connection pins for the 3 3V output JE4 and JE5 of are the high potential pins J13 a regular RJ45 connector on the E version board for PoE input and data link UE13 Bel Stewart Integrated RJ45 connect...

Страница 7: ...ectronic load It is not recommended to use additional filter capacitors greater than 20 F total across the output port as the extra capacitance will alter the feedback loop properties and may cause in...

Страница 8: ...er application If the proper response is not observed during both detection and classification modes check the connections closely If no current is flowing it is likely that the set of conductors feed...

Страница 9: ...RE2D in parallel to achieve a low cost AUX inrush limiter and transient protection Otherwise the unlimited inrush currents can wear on board traces connector contacts and various board components as...

Страница 10: ...p regulator output thus shutting off the startup regulator and reducing the power dissipation inside the IC Given the low current limit value 15 mA nominal of the high voltage startup regulator the VC...

Страница 11: ...e and directly enters full power application mode Horizontal Resolution 50 ms div Trace 1 PoE input voltage across the VIN and VEE pins 20V div Trace 2 Voltage across the RTN and VEE pins namely the v...

Страница 12: ...ET 3 Because linear current limiting is accomplished by driving the MOSET into the saturation region the drain voltage RTN pin rises When it reaches 2 5V with respect to VEE power good is de asserted...

Страница 13: ...ent Limit under 48V PoE Input and Output Dead Short Condition Figure 9 shows key waveforms of over current protection by the hot swap MOSFET s dc current limit The PoE input voltage is at 38V The inpu...

Страница 14: ...e Figure 10 shows the step load response at Vin equal to 48V The load current changes in step between 1A and 7A Horizontal Resolution 0 5 ms div Trace 1 Load current step changes between 1A and 7A 2A...

Страница 15: ...l 5 mA div Figure 11 PoE Input Current Ripples under Full Load Horizontal Resolution 5 s div Trace 1 The AUX input current ripples AC coupled 10 mA div Trace 2 The FFT of Trace 1 showing the peak valu...

Страница 16: ...r U6 along with a Syfer 1808JA250102MCTPY2 or equivalent for CE12 and CE13 24 Bill of Materials Table 2 Part 1 PoE Circuit BOM 1 ITEM PART NUMBER DESCRIPTION VALUE BR1 CBR1 D020S DIODE BRIDGE SMDIP CE...

Страница 17: ...S DUAL SCHOTTKY SOT 23 DIODE INC DE4 CMHD4448 DIODE SOD123 CENTRAL 125 mA 75V DE5 NU DE6 CMR1U 01M DIODE SMA CENTRAL 1A 100V DE7 NU P1 PJ 102A POWER JACK JE4 NU JE5 3104 2 00 01 00 00 080 POST MILL MA...

Страница 18: ...OR 21 0 k RE22 NU RE23 CRCW08051582F RESISTOR 15 8 k RE25 CRCW12060R47F RESISTOR 0 47 Ohm RE26 NU RE28 CRCW08050R0J RESISTOR 332 Ohm RE29 CRCW12062492F RESISTOR 24 9 k RE34 CRCW08050R0J RESISTOR 0 Ohm...

Страница 19: ...F 50V C49 CAPACITOR CER CC0603 KEMET E Board 8 pF 50V ONLY C50 CAPACITOR CER CC0603 KEMET E Board 8 pF 50V ONLY C53 CAPACITOR CER CC0603 KEMET E Board 8 pF 50V ONLY C54 CAPACITOR CER CC0603 KEMET E B...

Страница 20: ...ISTOR 220 Ohm R28 CRCW08051501F RESISTOR 1 5 k R29 CRCW06032201F RESISTOR 2 2 k R30 CRCW060324871F RESISTOR 4 87 k R31 CRCW06032201F RESISTOR 2 2 k R32 CRCW06032201F RESISTOR 2 2 k R33 CRCW060349R9J R...

Страница 21: ...OILCRAFT E BOARD ONLY U8 NU U9 NU U10 NU UE13 0838 1X1T W6 CONNECTOR INTEGRATED WITH ETHERNET TRANSFORMER BEL STEWARD I BOARD ONLY Y1 FOXSLF 250F 20 CRYSTAL HC49 US 25 MHz 21 SNOA476C October 2006 Rev...

Страница 22: ...sponsible for compliance with all legal regulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related inf...

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